The present invention relates to surgical cements such as bone and dental cements. More particularly, it relates to a surgical cement of controllable setting time which comprises a powdered or granulated bone substitute and a non-toxic, water soluble, low molecular weight polyfunctional carboxylic acid as a setting agent.
Surgical cements are used in numerous medical and/or dental applications including in repairing bone fractures, in attaching bone plates and other protheses, in bridging comminuted fractures, and in filling or aligning dental cavities. Examples of such compositions are described in U.S. Pat. No. 4,123,416 to Potter et al.; U.S. Pat. No. 4,271,057 to Drake et al.; and U.S. Pat. No. 4,376,835 to Schmitt et al. Granulated products are commonly used as bone substitute materials in dental and orthopaedic applications. These materials work well; however, the particles tend to migrate from the surgical site or exfoliate into the mouth in the case of oral surgery. Typically, surgical cements are mixtures of a ceramic and a polymeric material. The polymeric materials most commonly used are poly(meth)acrylic acid, polyglycolic acid and polyactic acid.
Potter et al. disclose that the gel and setting times of a surgical cement containing a fluorosilicate glass can be varied by the addition of an organic dicarboxylic acid such as tartaric acid. For this purpose, the acids are only used in an amount of 5 to 15% by weight based on the weight of the polymer.